Multicylinder internal combustion engine



Dec. 12, 1939. .1.v B. GABRIELsoN MULTICYLINDER INTERNAL COMBUSTION ENGINE Filedjbn,

'.5 Sheets-Sheet 1 1....,... im *HI-n n HB O uw 11.?. n .b 0 e a II UG 1| L TnIm A In n l v.. l.. e d.. In B O TU Dec 12, 1939 J. B. GABRlx-:LsoN 2,182,866

MULTICYLINDER INTERNAL COMBUSTION ENGINE Filed Oct. 15, 1937 3 Sheets-Sheet 2 23 Fui. 2l e# W 55%;

Intentar BS WARS.

John Bernhclrcl, G aarlELS-On DBC 12, 1939 .J.B. GABRIELsoN 2,182,866

MULTICYLINDER INTERNAL COMBUSTION ENGINE Filed Oct. 15, 1937 3 Sheets-Sheet John Bernharl 'GasrLeLsofrL B13 I ANAS.

Patented Dec. 12,1939

UNITED STATESv MULTIC'YLINDER INTERNAL COMBUSTION 1 ENGDIE y.mim Bernhard Gabieison, stockholm, sweden, assignor of one-half to 010i Edman, Stockholm, Sweden .ImplicationA October 15, 1937, Serial No. 169,133

, In Sweden October 15, 1936 1 1o clama (ci. 12s-171) The present invention relates to multlcylinder internal combustion engines.' More particularly the invention relates to such engines of this kind in whichl the outlets for the ,exhaust gases are arrangedlaterally of the cylinders, i. e. to so called side valve engines. The object of the invention to provide an efficient system for cooling side valve engines by means of currnts of air.

'It has been previously proposed to cool engines oi the side valve type by means of an aircurrent which is directed towards the exhaust side` of the cylinders and is brought to ow around each vcylinder either along the periphery thereof or in p axial direction along thecylinder, so'that the air currentl first takes up heat from -the upper portions of the exhaust side of the engine and thereafter sweeps along the engine cylinders proper. It has also beenproposed, in'cooling the exhaust side of the engine and of the cylinders according to the above described method, to let a separate air current sweep over the top side of the cylinder cover. However, systems .designed in the above indicated manner produce only an insuicient and uneven cooling, in that on the one hand a temperature rise which is detrimental tothe material cannot be avoided, and on the other hand deformations occur which impair the proper operation of the engine. i

`The inconveniences attendant to the previously known air cooling systems for internal combustion engines of the side valve type 'have been avoided according to the presentl invention by providing at the exhaust side of the engine one or'more flow paths for supplying cooling air to .the mutually adjacent portions of exhaust pipes and cylinders and for withdrawing l'said cooling air through van outlet opening positioned at the same side ofthe engine. tween an air inlet positioned at the exhaust side of the engine close to the exhaust pipes and an air outlet positioned at the same side of the engine.

The invention will `now be described more in detail having reference to the drawings attached to this specification and forming part thereof, which drawings show an application of the invention in an automobile engine. In said drawings Figure 1 is a view of the right hand or'carburetor side of an automobile engine provided with a cooling system according to a rst embodiment of the invention;

Figure 2 is a plan vlew ofthe engine according to Figure 1; Figure 3 is a view of'the left hand side of the engine according to Figure 1;

Figure 4 is a vertical section on the line 4-4 in Preferably said ow paths extend' be Figure 2 lviewed'in a direction towards the rear part of the engine;

Figures 5 and 6 are horizontal sections on the lines 55 and 6--6 in Figure 4;

Figures 7 and 8 illustrate a second embodiment'- of the invention, Figure 7 showing a vertical section on the line 'I-I in Figure 8 and Figure 8 a horizontal section on the line 8-8 in Figure 7;

Fig. 9 illustrates a front elevation of an engine according to Fig. 1.

` Such parts of the engine, for examplecarbretor, supply conduits, ignition esystem vand valve mechanism, on which the invention hasno direct bearing, have been omitted from the drawings for the sake of clearness.

In the embodiment according to Figures l to 6 are positioned in a common cooling chamber the roof of which consists of the cover angesG and the side walls of which are arranged at a suitable' distance from. the cylinders so that the latter can be swept over by the cooling air on all sides. On the exhaust side of the engine the cooling chamber is limited by a side wall 8 which joins with an end wall 9 vat the rear end of the engine and withl an end wall I0 at the fore end thereof. The wallsare supported by a bottom I2 secured at-the lower ends of the cylinders. According to the shown embodiment the walls 8, 9 and I0 and the bottom I2 are cast integral with the cylinders, as is shown mostV clearly in Figure 4.

The heat emitting surfaces of the cooled engine parts can be enlarged in known manner by means of cooling ribs. Figure 4 shows a manner of arranging such ribs. The engine cover 3 is provided with cooling ribs I4 extending transversely of the cover, the upper edges of such ribs lying in a common plane. The cylinders are provided with cooling ribsof -a direction, mutual distance and size which is adapted to the direction of flow and to the amount and distribution ofthe cooling air supplied. In the shown example horizontal cooling ribs I5 are provided on the front and rear sides of the cylinders, and Ivertically extending cooling ribs I6 are provided on the wall portions of the cylinders coinciding with the sides of the in such a manner that cooling air passages arev provided between. the end edges of the ribs.

An extension of the cooling air chamber (Flg ures 4 and 5), which surrounds the exhaust pipes 5, is provided with an outlet opening I8 extending along the entire length of the engine below the exhaust. pipes as well as with two slit-shaped smaller outlet openings I9 arranged above said pipes in a vertical cooling chamber wall 20. Said wall supports an air distribution duct 2| which extends along the entire length of the engine cover 3, 5, Il and has a ilow area which decreases gradually towards the rearmost cylinder of the engine. The lower wall 22 of said duct is connected to the vertical cooling chamber wall 28 between which and the engine cover 3 there is a free passage 23 for the cooling air ilowing out from the duct. The upper wall 24 of the duct `ioins to a hood 25 forming an air distribution duct above the cooling ribs I4 on top of the engine cover. The two ducts have a'common dividing wall 2l' which bears with its lower edge against the coolingribs I 4. At the left hand side of the enginethe hood 25 is bent downwards Yso as to bear against the upper edges oi the cooling ribsl. The openings between the cooling ribs form together the outlet for the cooling air which passes from the ducts Z5 and ZI over the cover 3. The cooling of the ribs Il and of the cover 3 is thus effected on the one hand by means of an air current coming from the duct 2| in a substantially horizontal direction and on the other by means of cooling air which is supplied from above from the duct 28. Through cooperation between said air currents an effective cooling is obtained also of the deeper portions of the ribs and of the free surfaces of the cover 3.

The cooling air chamber surrounding the cylinders has no wall on the left hand side of the engine (see particularly Figure 6). Through the intermedium of wall elements 3II of L-shaped cross section positioned at the two outer. cylinders the chamber is here connected to an air distribution duct 3l the area of flow of which decreases in the direction towards the rear cylinder. The main portion of the cooling air supplied by means of said duct sweeps over the cylinders and is discharged through the outlets I8, I9 positioned at the exhaust side whereas a smaller portion, after having flushed over the wall portion of the cylinders being nearest to the duct, particularly the upper part of said wall portion, discharges through free passages between the upper portions of the cylinders and a frame piece 32 provided for fixing the upper edge of the duct.

The cooling air passing from the duct ZI through the passage 23 and the greater portion of the air supplied to the cooling chamber by means of the duct 3| have thus common outlets. The two air currents meet in the chamber surrounding the exhaust pipes 5. The velocity of flowu will therefore become rather high at this point and on account of the different directions of iiow of the two currents at their entrance into said chamber eddies are set up which further increase the cooling effect. If required guide plates orthe like can be provided, of course, in the intermediate spaces between each group of two exhaust pipes in such a manner that the velocity of ilow around the pipes is still more increased. For the same purpose the outlet opening I8 can be divided into a number of smaller openings which compel the air to discharge near the exhaust pipes. The cooling air which from the drum 2| strikes the exhaust pipes disposed two and two close to each other and flows down between said pipes is, of course, heated comparatively much. To prevent said heated air from being carried inwards through eddies, a vertical guide plate 33 (Figures 4 and 5) is provided between the pipes. The plate is preferably made of a material having a good 'heat conducting capacity so that it will serve at the lsame time as a cooling rib for the pipes. It is obvious that the exhaust pipes 5 can also be provided with suitable cooling ribs and that guide plates or the like can be provided for directing the current of cooling air for example towards the under side of the cylinder cover flange 5. Plates for guiding the cooling air can be provided also at the engine cover 3. In Figure 4 is shown such a guide plate 35 which engages with tongues between the cool- .ing ribs Il. By means of said guide plate the cooling air carried through the duct 25 is divided into two currents of air which enter between the ribs consecutively in the direction of the ribs and produce together with the cooling air current from the distribution duct 2l a turbrlence which is favourable for the cooling action.

In addition to the above mentioned outlets for the cooling air coming from the cooling chamber suitable outlet openings can be arranged at suitable positions in the chamber walls. In Figures 4 to 6 such openings l0 are shown in the wall 'elements-30, and also in the end walls 9 and I 8 in the shape of circular recesses.

The supply of cooling air to the distribution chamber can beeiected in any suitable manner. Preferably, a centrifugal fan 42, Fig. 9, is used which can be connected directly to the motor shaft 58. The fan 42 is arranged in a casing i3 and connected with\ ducts 43 and58 arranged at the frontend of the engine with the air intake 59 preferably facing forwards. The duct I3 is connected to the fore ends of the distribution chambers 2l, 25 and duct in with the distribution chamber 3Ithe ilow areas of these ducts correy spending to the amount of air naming through the be regulated either by hand or automatically under control of a; thermostat. f

.In the embodiment described each distribution duct 2l, 25, 3i supplies two air currents each oi .which cools an appertaining portion of the engine. The air from the duct 2I will thus pass partly over the portions which are most intensely heated by the exhaust gases to finally leave through the outlet I8 provided at the same side of the engine,

and partly over the engine cover 3 discharging at the other side of .the engine. The air currents from the duct 3l pass partly along the sides of the cylinders facing the duct and to the outlet between the members 6 and 32, at which outlet an ejector action is caused by the air discharged from the duct 25, partly around the cylinders to the outlet I8, the cooling chamber wall 8 giving to the air current on the exhaust side of the cylinders a lower part oi' the cylinders.

aiaaeee are here surrounded with three casings 5l, 52 and B3 of which the casings Il and 52 form air distribution ducts correspondingto the ducts 2l, 25-

'airsupply arrangements can be of previouslyA i described kind and be connected to the ducts 5| and 52 in the manner previously referred to.

As should be clear from the above described embodiment it is essential for the inventionthat cooling air of a suiliciently low temperature is supplied to the mutually adjacent portions of the exhaust pipes and the cylinders and thus to that part of the cylinder cover plate 6 which is nearest to said portions. According to the two embodiments shown cooling air is supplied to said portions both from the exhaust side and from the other side of the engine, the cooling air which has passed the lower portions of th'e cylindersvand therefore has a comparatively low temperature being directed upwards, according to the iirst embodiment, by means of the wall 8 towards the cylinder cover. In certain cases the cooling air current directed upwards by means of the wall 8 will alone be quite sulcient` for cooling the portions in question of the cylinder cover and of the adjacent portions of the cylinders and exhaust pipes, the air current owlng upwards from the duct 2| or 5I respectively and directed to the exhaust pipes being then not requiredso that the cooling ai;` passage 23 can be shut oil". l

' The invention also comprises the case that the cooling air required for cooling the mutually adjacent portions of each cylinder and its exhaust pipe isadmitted through a separate air intake communicating with a separate distribution duct positioned below the exhaust pipe, the air being preferably admitted from below into the cooling air chamber enclosingthe exhaust pipes and discharged therefrom in a direction from the cylinders, for example through openings in the Wall 20.

I claim:

l. An air-cooled internal combustion engine comprising, in combination, a plurality of cylinders provided with a cylinder head and spacedly arranged substantially in line, exhaust valves `and exhaust passages positioned along one side of said cylinder head, exhaust pipes connected with said exhaust passages, means forming a passage-way for a first current of air for cooling the top of said cylinder head, means forming another passage-way for a second current of air 1 for cooling said cylinders, means forming a third passage-way for a third current of airv for cooling said exhaust pipes, said passage-ways for said three separate air currents extending substantially perpendicularly to said line of cylinders, a fan assisting in `producing said air currents and air distribution ducts leading from said fan to 'said air passage-ways.

2. An air-cooled internal combustion engine comprising, in combination, a plurality of cylinders provided with a cylinder head an'd spacedly arranged substantially in line, exhaust pipes extending from the underside of said cylinder head .laterally of and spaced from said cylinders, a first air-conducting jacket surrounding the top of said cylinder `head, a second .air-conducting.

jacket surrounding said cylinders and including portions of said exhaust pipes facing said cylinders, said second jacket having inlets arranged at a side of said engine opposite to its valve side and outlets arranged at said valve side so as to cause air to iiush over the cylinder walls and then to pass over said inside portion or' said y exhaust pipes, means ioi' directing a third current of air towards outer portions of said exhaust pipes, a fan assistingin producing air currents passing said jackets and directing means, and air conducting means leading from said fan to said cooling jackets and saidair directing means.

3. In an air-cooled internal combustion engine as described in claim 2, baiiiing means for leading said third current of air, after being heated through contact with said exhaust pipes, spaced from said cylinder walls.

4. In an air-cooled internal, combustion engine as described in claim 2, said ian arranged at one end of said'engine and said air ducts extending from said fan along Vthe entire length of said engine.

5. In an internal combustion engine as described in claim 2, said directing means for the third current of air being arranged so as to direct said air towards portions of said exhaust pipes positioned adjacent to said cylinder head.

6. An air-cooled internal combustion engine comprising, in combination, a plurality of cylin Veyngine,above said exhaust pipes,'said iirst duct having outlets for supplying cooling air to said rst and thirdl jackets, and a second air duct extending from said fan along a side of said engine opposite to said valve side, said second duct having outlets for supplying cooling air to said second jacket.`

'1. In an air-cooled internal combustion engine as described in claim 6, said second and third jackets having a common outlet arranged at `said valve side of the engine.

, 8. An air-cooled internal combustion engine as described in claim 6, characterized in thatfa wall of said second jacket which extends along said cylinders on said valvevside of the engineis arranged to lead said second air current along said cylinders in an upward direction towards the cylinder head, said jacket wall having an upper edge adjacent to the underside of said` exhaust pipes, sothat 'the air is forced first to flush over the cylindersand then to iow towards said pipes.

9. In an internal combustion engine as described in claim 6, a third air duct extending along said engine above said cylinder head, said third duct provided with outlets for discharging a f ourth current" of air towards the top of said cylinders.

10. An air-cooled internal combustion engine comprising, in combination, a plurality of spacedly arranged cylinders provided with a cylinder third separate passage-way for a third current of air 'for cooling said exhaust pipes. said passage-ways for said three separate air currents extending across said cylinders, and means for .supplying cooling air to said three separate 5 paSSiLge-WEYS.

JOHN BERNHARD GABRIELSON. 

